While the use of teleconferencing is continuously growing there is a growing demand for secured communication in teleconferencing. The need to provide secured communication in teleconferencing sessions imposes a technical challenge as the number of active participants in a single teleconference is expected to keep growing in the future.
Secured communication consists of two principal requirements: encryption of the data and authentication of the data source, i.e. the sender. Generally for the purpose of authentication the source of data should not necessarily be identified as an individual or single entity, but may also be identified as a valid member of a group.
In distributed conferencing systems a packet of data is transmitted by a speaker and is distributed to all other participants through a group of servers. According to the common practice that is performed in non distributed conference application, each server needs to authenticate the data source, to decrypt the payload of the packet and then re-encrypt the payload, clone the packet for each destination that the packet is designated to, and re-calculate and attach an authentication tag for each destination that the packet is designated to. This list of actions is time consuming and when the number of participants in a conferencing session exceeds a certain amount it will be no longer possible to guarantee reasonable end to end distribution times as required by real time applications.
Current secured teleconferencing methods and systems are heavy CPU consumers and suffer from long latencies in the media passage. There is a need for a method and a system that enables to reduce the time that each packet is handled by the servers in a teleconference application in order to guarantee reasonable performance in scalable secured teleconferencing sessions.
PCT/IL2007/000202, filed on Feb. 13, 2007 “Method and system for controlling a distributed data flow environment” (referred to as “data control method application”) describes a method for controlling data flow in a distributed system. The data control method application refers to a distributed system that defines also an hierarchical structure of servers where each or part of the servers are provided with the number of active speakers in the system, and whenever a server gets data from a son-server or from a client it can decide whether to distribute the received data or block it according to some parameters including the number of active speakers, a predefined number N of maximal active speaker and additional arguments e.g. if a specific data sender is defined as a high priority sender. Each server or part of the servers when deciding not to distribute the received data also send a control message to the sender (source/creator of the received data) to stop sending messages—in this way the load on the network is reduced and its efficiency improves. However, for implementing this method, the server must be able to identify each speaker/sender.